He is a child, always mismanaging his life.
"Modeste Mignon"
Honore de Balzac
When a girl reads sentimental and passionate poetry, neglecting Scott, Milton, and Wordsworth, I call it the same sort of wrong mismanaging of herself as if she ruined her digestion with a greedy love of pastry.
"Stray Thoughts for Girls"
Lucy H. M. Soulsby
As Greystock had said, everybody was at law with him,-so successful had been his father in mismanaging, and miscontrolling, and misappropriating the property.
"The Eustace Diamonds"
Anthony Trollope